Going into the tournament, a No.2-ranked Wozniacki knew she could overtake Serena Williams for No.1 if she reached the quarterfinals - but there was a lot of work to do. After a first round bye, she went down an early break in her second round match against Sara Errani but rallied to win, 64 62.

"I felt like I did what I had to do to win my match today, and I'm happy to be through to the third round here," Wozniacki said afterwards. "But tomorrow is just another match - hopefully I can win it."

Kvitova posed even more of a threat the next day - she had beaten Wozniacki easily at Wimbledon that summer - and the big-hitting Czech broke in the opening game. But she was just too erratic for her rock solid opponent on the day, one last backhand into the net giving Wozniacki a 63 62 win - and No.1.

Wozniacki threw her arms in the air as Tina Turner's Simply The Best played and cheerleaders ran out.

"I'm very proud I can call myself the No.1 in the world now," an elated Wozniacki said in her press conference afterwards. "It's an incredible feeling and something I've always worked for to achieve."

The classy Dane also had gracious words for Williams, the WTA legend she was replacing at the top.

"Serena has been injured for a big part of the season," Wozniacki said. "She's a great champion. What she has achieved in her career is a dream for me to achieve. I'll always see Serena as a big champion.

"For me right now, though, I should just enjoy my moment."

Wozniacki officially rose to No.1 the following Monday, October 11, 2010. She stayed there for 67 of 68 weeks until January 30, 2012, when Victoria Azarenka took the top spot from her. The only week in that span where Wozniacki wasn't No.1 was the week of February 14, 2011, when Kim Clijsters took it for just one week (becoming the first mother in the history of women's tennis to be World No.1).